A molybdopterin that is the <element>O</element>-phospho derivative of [(5a<stereo>R</stereo>,8<stereo>R</stereo>,9a<stereo>R</stereo>)-2-amino-4-oxo-6,7-disulfanyl-3,5,5a,8,9a,10-hexahydro-4<element>
H</element>-pyrano[3,2-<ital>g</ital>]pteridin-8-yl]methanol. ChEBICHEBI:44074